SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32a5dd252feb2cc4a7c61983c573ad290bea43ce48b82bb367528f2b3f34b703' 
  AND token = '0SqrzDHuItT+DJnH4dRFnxaJTpSLPEjgdrVySFxYCQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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