SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71cb8c9c0b34a7b783565119277a855075a134316850b16d024117140a50b2b0' 
  AND token = 'Kw2m5BsjRo46TchutMTv/AXMk+hlYuD4xPv6i9coFFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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