SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0a718281f0960295de9eb781ae686514473df246d6dccb196493f36d0432329e' 
  AND token = 'sDk5Qz5J0sljZADWbOzQKu/Mhz9cPPC0Nb/ZvrQafx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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