SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d20b9d272f3ee30fcd09e0f3a4ed4d928d1e8decd2f7ff507064b41702a7130' 
  AND token = 'A7qeFo8QvlR+fuFksDiyzWMMRYcdE7tV5WtxYyfB780=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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