SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00a02debf7db86f499df77a64600edd1bb92d3967b8f7becabc44fee443fdcf0' 
  AND token = 'ulwN2fIZQ1gB3etRZGRMC902vFToElMBKkmWQbWMMtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}