SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5070d52d13d654da64cb1a31bb88ed12a8ac936fca8847cb55026764f1ac1ff' 
  AND token = 'bz68VIHQcYuXKjOsv19mUTi+TQ3X9j+CiABYguOPpV0=' 
  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"
    }
  }
}