SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102e135bc1b2cf2eace48203125d6e7770d23b0fdd620552efe46ce00a14d24d' 
  AND token = 'EVWSfAI94DyBEWRCC52Eml86JPVxcuCOSE7qM0PjUSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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