SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bb02189bad22729dc9d157891bd9e33ccefc1b03bb5c76358dd178641196f86' 
  AND token = 'VxcminGapFGo7Kh9R82OcM7FW8jU3JDVxHUHAGIh1xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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