SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45ea4fdb45539b8bb27bdd1beb86940b72bc7160de7891d43412cce1c09ffbdc' 
  AND token = 'Dt3DIVXER6c1EUthPAGKZD36YNNJjxoxG1CzrGEomDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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