SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf68bcf3f5fe1828fd47eb0937e67323cac4fdb4efffab47543269084d269547' 
  AND token = 'iaDiqAAFMBZOPwnq4TBIre+7hkH/s3R45JvEW4ZVHpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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