SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0561e7a492206de942f6b565b022dd7261b1df3f617ada7aeae391c9b440fb6' 
  AND token = 'JKCzfn4EoQk5Y64Yyuq5hOUFCHQpoQsUp3rTtI3dcRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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