SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd66be28aa871d7c7b63bb640a5f4832d8145f78422cb51c23e235181aa681f61' 
  AND token = '63mR0xacbNFxFxvW4ZlyVpYIUpfbUx65W4UREx2cumk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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