SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12382d11efcc0a91da3710e1512962607a39b6c4e9d25e26d9570e08de67a145' 
  AND token = 'M2kvMKJvQCebUuRi8YdqnJA/yBwCVbZxMxRdR1UYM2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}