SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd05c2a14e0a008e98bf9369d8511c0c73cb6582af1627c9f16e2475a09e758' 
  AND token = 'LCgZi4SWnFJXI0gkXytKDnw1wDPq/+1vEuw/k26F2ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}