SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '90cb5bdb2a00649d1f292ac66792598f1475539cc82c7a8a119f8bfdd069ecbe' 
  AND token = '2mr/iB5/f+o4IfvhlzCrAxx4oPs+WhCSYezAXzKo73A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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