SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a03f6deab98fa1aab8634d59430d84e512ef67317f5b0c8fcbdfb4ac875d34' 
  AND token = 'i2l2mNC/OfJSKangPS3zzsSbJNtYC0npRumBGGfRg4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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