SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c9374fc810238ae6fb7e9d02c80231cffbb69da2a1baf93af478fdee78001d' 
  AND token = 'zBRnZoCA5IukmWMasLpZ7K7ns+FYjMFLpN8lvMG7lJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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