SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21569b40582173038299f23fc2f2b563a5409d78f366afa64342878d95e54592' 
  AND token = 'Po7adCvq/pk/8ap/MbcnwWa1UmLmL4Q/GPCBAPxYRd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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