SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd704a62a101a6b5bdb0772a74c7bb4ed2b0e3899876bf255ffe2102dcf0bff6e' 
  AND token = 'sBbfcAKwLlHQjFW+27X5jshymuyYzFl/pgi/Ax6NGso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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