SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88ca13f86a29cd529a24cbd35e87337dcd527e99e794ff4404d3f72be0405831' 
  AND token = 'jxxtuVoANMygc0L1S92+WKGlh0Lv/otAg3GYm7zZDEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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