SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a0a49fc1e83240051a1dfad7258004a0ff4675c5bc821d9eccb476b867e547a' 
  AND token = 'vbf4JGwsRAznZDefLM308qlFPG7wgDNhxsTQBk+VtYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}