SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9601e5afb03a2ffea2ee450471a9300d6110987b0693ed08ab760b89f68ad4d5' 
  AND token = 'HhpUMHjBqvP4SLSfHP4CJojcWGQoIGaEgNaMrSyjd/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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