SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479bed8b81f3ed64ae31870e7d0bdcbfcc66141b1ab772546ec97fc61207fd43' 
  AND token = '1yt5EeV4XDT/kYh4zgoK09Ke+nYy3S0E2A+M4o1YBKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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