SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '127f6476f595cd129139c1989b567bd23844fd418156b908a5876777b6afdde3' 
  AND token = 'W6w1+rK937QFTOqvumcoca4XG4/o7BOqfA40vrxWriU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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