SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daebdba10baca13e42a90e02c1938538f316fcf6bc4601c7afa897b91edbfe36' 
  AND token = 'mUR5VfXdnrbGGcNcWbtCTrfRC8XHGoOq6xbrwiP3Q3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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