SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bc67c4b5af3b3218e17af1874b75286eeaab8199dda0d00b17501acfca581f' 
  AND token = 'jMnLYa+i+YK+4+/Qk1dt5M/tATJ9nKDH+jR4wepHTHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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