SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9cf20b14a19274bad620abd80f5530a4f98d7bbec50ccc83a71438a73b498c03' 
  AND token = 'nnn+AcLidab7yxgyuK2r2Ob5fejXfr4YticdbQ5FHgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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