SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0365d83ba7ff54bada1bf9aca6f6d91dc59dae5449bbe99a4cdb98b605227fa' 
  AND token = 'ACD+x/pzVGf7Thsq8ZkuN3o/j6pCt31S/6x2PgTZqWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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