SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4883014eb53a53796ce59ffd6f0f3f763fa481d5ac5f46c122bf75ebcb19919a' 
  AND token = 'X5li/sr9QrRUieQyoIwmsNt32WyPHgPLv6EwsmsBwHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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