SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd32b2d5da2c80c88c1b5c0709afaff7a3c9726c759b2b2f4d5881791f8bc7760' 
  AND token = 'aSz/dGV6RgKYUkS63sfkXPXZNwVh8W/qqsW0bSqWBN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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