SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7a15644fe7c97155391b00ece643205e7025d273ecea0eb948bf6ebbbcd6649' 
  AND token = 'SNgVZgXCZzopDJ4jVCIW3A/fUExrDpF07VqBfhGQ1iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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