SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b6c07ea7f17811b1d586ffe87146fe97fdbc2f02ca226930f9708fc88863a3' 
  AND token = 'Ms57XTIKx5JcLMULBG4t7MzTgHpojMJWpvWxtExidgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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