SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785487cd1c33e2fbe7571b8a424cf2464e11f8b19b919e273f5d4b2dafadb2cb' 
  AND token = 'wHI+Ko/F7njXiEtJfiNzzzUigum91XRBLEFby+Rh050=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}