SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864b0ef22135a158dc83335c7326caa204829afd0ed1d748a966b0ff1eb984b1' 
  AND token = 'o2CVJ0kQBfLM+jm1nafwJruzr6/Ukpi2dvFcFTDrHAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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