SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b273d9825eedc35b2bc115ecb18b6d876597ca65bf32a3391d1e2e06300d92' 
  AND token = 'vdomXmstnB5ATDJjJICO3SsHNc+Lb3GhA5xQm1A2oz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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