SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87c74d178281c8b51233887ae3809f1c25e86a3c05d618b0b6f2c613202281e4' 
  AND token = '0ET3NH73og2VxD7VJZUgBVI8K/HdWnCRhpgIAESzN2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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