SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20cb1eca9d44094c9310de2b0042f89ad9183b9be45a4f9bc6a7808773759059' 
  AND token = 'DPnnKSPiYAtFmGtfwNiYyaf7bk8uEsLRlvipz0g+5Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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