SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '922dc283498524ff3698e6c75e5516b55519da7e0787ca86389bfe51c4d7c599' 
  AND token = 'eRHMx0rCTh25X6gjqUXxR7i3CmXalJGwFRTIXbgChuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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