SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74720c785f5579a7538dd383ebf91c21c5cfd38168867bcfe9b63fda74ec5bd6' 
  AND token = 'inFNalmvqd3ufY47kBMBRLaJ1rTQV8Xr2UcMERepb+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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