SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3a0e07c771546804c55c17fa9354668efd801ec6912c32e95fcc6fe9a413cb7' 
  AND token = 'fZfNR+l/mjAT3fxUXu/Jjl9glaK2HeCVgmcu9VDGMrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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