SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57edee64ac1d5d1d7bffccc2362b777cbd2d5f9472e6470a8f0590a14a7cb514' 
  AND token = 'DKzjLL27f7XTLDnX6l/5/PxH5oeq6q3PkKZ0aXa5yd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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