SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f23e6c231dfeed9cfa4e57f13068ac64393421a1ccc04fbb406d5abfdc2d9eef' 
  AND token = '6zLfBQOJEi/GX7BG+owzp5vRaH0pG3Q3PLmEuNyTFfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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