SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ba372570766a19f27465b60242452a01caf633b2dffc5cf42e421c8b7d065e99' 
  AND token = 'q6q2MvAtq/jeRYTuneM6//a1hKe7Hoes6yBu9XRldU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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