SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f628525c6fc0f932903e88f555a92629f2cdb271c6d2f01377ed3346cb5aad' 
  AND token = 'sHNgxffyu1/g2goMZdnqJb2R5k6Ra1DY4HWarSGaY98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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