SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddb0f4445bdccadc43129451a4d61ca6872478419a2df05f21feae12f5f25c16' 
  AND token = 'sBAs6iF3DGQirrPYDUnGyWE5hWFBPqZ21K9VxWChUVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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