SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8ab90a45c1f770c698fbfda381a94d862411aa367f99ca018554de3a27667fa' 
  AND token = 'XHezR2rqHkoPuPn8XaAuEqM8P//dU2rW5JBrWM7D8Cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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