SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37fae98b76449b7ee089ecc64613dce49771f19136822cc175258dcaa448086a' 
  AND token = 'Ht5aDZko70QINgOWjCceqIpU/HmA2xn8U5HkKEMPgao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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