SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e5d6df4cf665d462c6dec292275ff7a30be4aa97afadf96cc0f062483f4dd97' 
  AND token = 'fBixmieU1c4SsQaWgoVrbxvv916R82usq2Ck6prhmu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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