SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f034ede41a2b76038534edaedd1083084e1a8660cc9a02895893e1e236743bb5' 
  AND token = 'tKxosfb9BsTIx+j9fpXEYItxVCV7wBL/6+nbr0ItCsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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