SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ed17487fb7ddf08326ef10ec36bf9b7c5fc8f0222836f764e768b0dfc1affb' 
  AND token = 'oxxGqCFkogA+nu9ZcGUTWSflJhrk4eFKZX+EDMcClBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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