SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bec6244f8814a95ee818c4c086b0c0dfb90c23d064f1feb84c87799021f792e' 
  AND token = '5KwnJdi3M1rqfC6N4MT0fcksK8B0QDHTblnvk8orrrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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