SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1406c4c76cd98f5333abfba565522ca5b46fdd4a9ae4c2e6e556cde9c166873a' 
  AND token = 'lXSLYMEPSpaZkI2TohbReVwoNowoQh/uCQ/z3RReZbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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