SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23482b5151ce9fb5751c8817acabe886d0683bba9d68b3d384e81be92fee6d8c' 
  AND token = 'LQ/yz+D/HhwoByxN0+nwlcsKTTr9xhhW2rYCUL0k2BE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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