SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2c254c68a2e6bc6f3b743c953d3ba1dd314753fc78f2c96dbd5337f7733daa2' 
  AND token = '6pVQ8PhWOVHjpHc2KKWP5Lo2vRaz8Bha8YpqsfT+Zg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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