SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eaf9b8ae276ce7399ce55297fa9ac9cd2ecf878fd35a1be546140933e74ba6a' 
  AND token = 'olPzP4Ln+OTB6R/CgXkqxYEQBP0KpCd+cfv2ZflQj54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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