SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '199982f99de64da9cd65153af121b2304c20c80122a02c70df966eeb5a033f3e' 
  AND token = 'OriZbjyxXtbT231UI+apXPqbtf30a7biXAACbiknB8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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