SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '159e3bc4a4ca2b7c59749404923f988c1e1b4b7d59ef894162d21c8f157690d8' 
  AND token = 'QezwU8HKZ7CMNulE/RFbrVJqSI6Z46g+I2S0GRqjm6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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