SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4497456092ede757d5712fd9ddb2455f8f431eacb3448baf83361c42d018659' 
  AND token = '0fodJMHRUueoFlDg+prjNA3hs+uwMQWufO2VB4Cs8JE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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