SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1ab23333330b189c8ae1d3c1865a9223fdaa7ebca7bb05bd5255ce9091d692d' 
  AND token = 'QNGwXZtRviE5CtWG3ZBAtk0C6aNffUfEi0bt51CHhv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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