SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b70d3e17bff40fc7c17de9aedae00503216882db25247557148635f47e04aae1' 
  AND token = '/fb3eaKQtrGyQLgLaIFTQSth5alr9WSDyjCKiSomr/Q=' 
  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"
    }
  }
}